Guelph-Wellington Master Gardeners

Tips for watering houseplants

Watering houseplants is one of the tasks that gardeners err on most. Perhaps it comes from the human need to have schedules, watering plants every week, not realizing that some may need more or less water than others. When a plant needs water, as everyone knows, the leaves wilt. When a plant has what gardeners call “wet feet” – the soil is saturated with water – symptoms are the same. This is because plant roots need oxygen, just like humans do, and suffocate when the soil is too wet.

A common plant like spider plant (which, by the way, is fantastic at removing carcinogens from the air, and therefore a good plant to have in your home!) likes a moderate amount of water. Another great bulletproof house plant is the snake plant, with its long rigid sword-like leaves and, often, bright gold edges. Snake plant requires VERY little water and despises wet feet. (Interesting that two of these icons of the house plant world both have animal names!)

It probably seems obvious that these plants shouldn’t be on the same watering schedule, and yet that’s what we often do – once a week whether they need it or not! The answer to the question “How much should I water?” is not the simple one folks are looking for. The ONLY way to do it right is to stick your finger in the dirt. If it’s warm and dry, give it a drink. Don’t let water sit in the saucer underneath for more than 48 hours. If the soil is cool and moist, leave it alone and check it in a couple of days.

A technique that WILL give a bit of extra latitude is to have the plant, and its pot, sitting on a saucer of pebbles so that it isn’t sitting in water but there is an envelope of humidity around it. Incidentally, lots of folks ask about the brown tips on spider plants and other long-leafed plants. This is often caused by toxins in the water such as fluoride.

The plants are trying to get those toxins as far away from the heart as possible, out to the tips, which then die. It’s OK to cut these tips off. It looks a bit better if it’s done on an angle. A partial solution is to let tap water sit overnight before watering, or use rainwater.

On the other side of the watering spectrum, one of the biggest errors encountered in plant care involves orchids. Orchids are INCREDIBLY easy to grow.

The most common cause for stress is feast or famine, in terms of watering. Orchids actually ARE a plant, generally speaking, which can be put on a regular watering schedule. Once a week soaking in a bucket for a few hours is the easiest way to water them.

While some folks may have had luck with the often-recommended ice cube method – just letting a couple of ice cubes melt over the roots, it’s generally a BAD idea. While it may be a good way to slowly release water, imagine if you were a tropical and had ice water being dripped on you. You wouldn’t die right away, but it would make you feel pretty horrible most of the time. Throw that ice advice away. Let’s never hear it again!

— Sean James, Guelph- Wellington Master Gardeners

This post was first published in the March 2018 issue of the Puslinch Pioneer.